Buffalograss plant named ‘UCD-95’

ABSTRACT

A new female diploid cultivar of Buffalograss (i.e.,  Buchloe dactyloides ) is provided that resulted from mass selection. Superior turf quality is displayed over the entire growing season. The stolons are of fine texture and the internodes are short. Good drought tolerance is displayed. The plant exhibits superior turf green color retention and short winter dormany. The growth habit is extremely competitive with respect to weeds. A high turf density is made possible with a rapid stolon spreading rate and short plant height that provides an attractive low maintenance turf.

BACKGROUND OF THE INVENTION

Buffalograss, Buchloe dactyloides (Nutt) Engelm., is recognized to be awarm-season stoloniferous, sod-forming, perennial grass. It is a droughttolerant and an important range grass found mainly in the centralprairies of the United States with its full range of distributionextending from Canada to Mexico (U.S. Agriculture Handbook, 1959). Thebuffalograss is the only species of its genus. It contains diploid,tetraploid, and hexaploid races (Stebbins, 1975), of which only thelatter occur in the Great Plains area.

The diploid race mainly occurs in Central Mexico and southern Texas(Reeder, 1971) and it has only recently been researched for economicvalues, especially for turfgrass development. Genetic variation inshade, cold, and salinity tolerance has been detected among buffalograssgermplasm collections (Wu and Lin, 1994, 1996; Wu and Harivandi, 1995).Allelochemical compounds found in buffalograss function as abroad-spectrum preemergence herbicide. Accordingly, they are potentiallyuseful traits for buffalograss breeding (Wu et al., 1997).

SUMMARY OF THE INVENTON

The new cultivar of the present invention is a vegetatively propagated,drought resistant female buffalograss clone resulting from massselection. Seeds of diploid buffalograss germplasms were collected fromlocations in Mexico including San Jose, San Clayetano, and Venegas. Thepopulation sizes of the three population were 215 from San Jose, 250from San Clayetano and 300 from Venegas. Plants were established fromthe seeds and these were space planted during 1987 in an experimentalfield at the University of California, located at Davis, Calif., U.S.A.The plants were mowed on a weekly basis at a two-inch height during thegrowing season from May to the end of October.

Individual clones were selected for rapid vegetative growth, high turfdensity, and extended winter turf green coloration. Approximately 80percent of the plants were eliminated during this selection for theabove characteristics. The remaining plants were subjected to droughtstress by terminating irrigation during the following summer months fora period of eight weeks from June 15^(th) to August 18^(th). Two maleplants and two female plants were selected from each of the threepopulations on the basis of their superior performance. The six male andsix female clones were grown close together in the field to achieve masscrossing and the resulting seeds were harvested from the female plants.These seeds were germinated in the greenhouse and grown for six weeksbefore being transplanted into the field. Approximately six hundredplants were space planted in the field and were subjected to turfgrassmanagement. More specifically, the plants were mowed weekly to a heightof 2 inches, were irrigated every 10 days, and in April and in Augustone pound of nitrogen was applied per 1000 square feet as ammoniumsulfate. Two clones from this planting previously were selected and werereleased. These were the ‘Hilite 15’ cultivar (U.S. Plant Pat. No.8,896) and the ‘Hilite 25’ cultivar (U.S. Plant Pat. No. 8,897). The newcultivar of the present invention additionally was studied and evaluatedand was selected and carefully preserved as a result of its exhibitedcombination of characteristics.

It was found that the new diploid female buffalograss cultivar of thepresent invention exhibits:

(a) stolons of fine texture,

(b) superior drought tolerance,

(c) a competitive growth habit,

(d) short winter dormancy

(e) superior turf green color retention, and

(f ) high turf density with a rapid stolon spreading rate and shortplant height that provides a low maintenance quality turf.

The new cultivar of the present invention can be readily distinguishedfrom the ‘Hilite 15’ and ‘Hilite 25’ cultivars by shorter and thinnerinternodes, fewer burrs per spikelet, smaller burrs, and fewer flowersper burr. As reported hereafter, under field management conditions atDavis and Riverside, Calif., U.S.A., a superior turf quality wasdisplayed over the entire growing season by the new cultivar of thepresent invention. Also, a greater vegetative spreading rate, a higherturf density, greater injury regrowth potential, greater shadetolerance, and better turf green color retention in the fall have beendisplayed by the new cultivar. A greater dry weight allocation in thevegetative growth and a lesser weight allocation in the sexualreproductive parts have been displayed by the new cultivar.

The new cultivar of the present invention has been vegetativelypropagated by the use of stolons, sprigs, and plugs. Such asexualpropagation was carried out initially in greenhouses at the Departmentof Environmental Horticulture, University of California, located atDavis, Calif., U.S.A. Thereafter vegetative propagation has been carriedout at Riverside, and near Anaheim, Calif., U.S.A. Such propagation hasconfirmed that the characteristics of the new cultivar are stable andare reliably transmitted to subsequent generations.

The new cultivar of the present invention has been named ‘UCD-95’.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs show typical specimens of the ‘UCD-95’cultivar as depicted in color as nearly true as it is possible to makethe same in color illustrations of this character. The plants were grownat Davis, Calif., U.S.A.

FIG. 1 shows for comparative purposes representative stolons of the newcultivar and that of the ‘Hilite 15’ and ‘Hilite 25’ cultivars whereinthe shorter stolon diameter and shorter internode length of the newcultivar are displayed.

FIG. 2 shows typical sexual reproductive parts of the new cultivar aswell as those of the ‘Hilite 15’ and ‘Hilite 25’ cultivars forcomparative purposes. Smaller and fewer burrs per inflorescence aredisplayed by the new cultivar of the present invention.

FIG. 3 shows a typical container grown plant of the new cultivar duringthe summer.

FIG. 4 shows for comparative purposes a typical container grown plant ofthe ‘Hilite 15’ cultivar during the summer.

FIG. 5 shows for comparative purposes a typical container grown plant ofthe ‘Hilite 25’ cultivar during the summer.

DETAILED DESCRIPTON

Reference to color is based upon the Inter-Society ColorCouncil-National Bureau of Standards Color Chart (September 1988).

The new cultivar of the present invention is particularly adaptable toareas of the California central valley and southern California, thetransition zone of the United States, and from Central Mexico to thesouthern portion of the Great Plains of the United States. Its growth isbest in direct sunlight with temperatures above 20° C. Its performanceunder shaded conditions is comparable to bermudagrasses.

The new cultivar may be established by planting sod, springs, or plugs.Planting two-inch plugs on 12 inch centers establishes a solid turfcoverage within 10 weeks (from June to August). It is a female plantwhich is a vegetatively propagated clone and spreads by stolonization.‘UCD-95’ does not produce male inflorescences as appear in seededbuffalograss. Nor does it produce viable seed in the absence ofpollination. It forms a dense, uniform, fine-textured, stoloniferous,deep green turf. In the absence of mowing ‘UCD-95’ reaches height ofapproximately 10 to 15 cm. It requires minimal water, nutrition, andother maintenance. ‘UCD-95’ displays dense and aggressive growthcharacteristics that render it highly competitive against unwantedweeds. In ‘UCD-95’, aesthetic attributes of density, uniformity, andappealing turf color combine with durability, competitiveness and lowmaintenance requirements. Together, these agronomic attributes render‘UCD-95’ particularly suitable for home lawns, recreational turf areassuch as the fairway and rough of golf courses, industrial parks, andground cover along roadsides. ‘UCD-95’ is further characterized in thefollowing information and Tables as observed in greenhouses andexperimental fields of the University of California at Davis, Calif.,U.S.A., except where otherwise indicated.

The leaf color of ‘UCD-95’ is deep green (118 deep YG) when undergoingactive growth and changes to yellow (73. p.OY) when dormant.

The ‘UCD-95’ Cultivar

Origin: A single superior diploid female buffalograss plant selectedfrom mass crosses of three diploid buffalograss germplasms collectedfrom central Mexico. Plants used for the description wereapproximatively 10 years old.

Classification:

Botanical.—Buchloe dactyloides (Nutt.) Engelm.

Chromosome number.—2n=20.

Form.—Monocot Gramineae.

Growth habit.—A stoloniferous vegetatively reproducing female plant withshort vertical growth and a rapid horizontal growth rate. Its fibrousroot system knits in most media within three weeks from plugs or stoloncuttings. In season, it produces dense, uniform, fine-textured turf andholds its green color to near the freezing temperature during the wintermonths.

Establishment rate:

Sod.—1 to 2 weeks.

Plugs.—6 to 8 weeks (in July and August).

Springs.—6 to 8 weeks.

Regions of adaptation.—From central Mexico to the central Great Plainsof the United States and is particularly adaptable to areas of theCalifornia Central Valley and southern California.

Blade.—Shape. — Long, slender, with pointed leaf tip.

Length.—Approximately 8 cm on average.

Width.—Approximately 1.2 mm on average.

Hairiness.—Absent, is glabrous.

Mature plant height.—10 to 15 cm.

Internode:

Length.—Approximately 57.6 mm on average of 2nd internode from the tipof ten stolons of greenhouse grown plants, and less than that of the‘Hilite 15’ and ‘Hilite 25’ cultivars.

Diameter.—Approximately 0.64 mm on average of 2nd internode from the tipof ten stolons of greenhouse grown plants, and less than that of the‘Hilite 15’ and ‘Hilite 25’ cultivars.

Node pigmentation.—Purple (259.d.p R).

Stolon color.—Green (120.m.YG).

Leaf color:

Active.—Deep green (118. deep YG).

Dormant.—Yellow (73.p.OY).

Soils.—Heavy clay, silty clay, loam, calcareous, neutral to alkaline.

Inflorescence:

Male.—Absent.

In the Tables that follow, characteristics of the ‘UCD-95’ cultivar ofthe present invention are compared to those diploid buffalograsscultivars ‘Hilite 15’ (U.S. Plant Pat. No. 8,896) and ‘Hilite 25’ (U.S.Plant Pat. No. 8,897), and to the well-known hexaploid buffalograss‘Texoka’ cultivar (non-patented in the United States). In the Tables,“P” designates “present” and “A” designates “absent”.

TABLE 1 Morphological Comparison ‘UCD-95’ ‘Hilite 25’ ‘Hilite 15’‘Texoka’ A. Vegetative Traits 1. STOLONS P P P P a. Color and GreenGreen Green Green pigmentation (120.m. (120.m. (120.m. (262.gy. YG) YG)YG) pR) b. Internode length (mm) 57.6c* 70.1b 59.5c 95.0a (mean value of2nd internode from the tip of 10 stolons of greenhouse grown plants) c.Internode diameter 0.64c 0.71b 0.76b 0.90a (mm) (mean value of the 2ndinternode from the tip of 10 stolons of greenhouse grown plants) 2.NODES a. Color and purple purple purple purple pigmentation (259.d.pR)(262.gY. (259.d.pR) (259.d. pR) p.R) 3. RHIZOMES A A A A 4. LEAF BLADEa. Color (1) Active deep green deep green deep green blue green(118.deep (118.deep (118.deep (164.m. YG) YG) YG) bG) (2) Dormant YellowYellow Yellow Yellow (73.p.OY) 73.p.OY) (73.p.OY) (164. mbG) b.Dimensions (flag leaf) (1) Width (mm) (mean 1.2b 1.2b 1.2b 2.0a value of10 samples of fully extended leaves on 2nd internode of each stolon) (2)Length (cm) 8b 8b 8b 13.0a c. Hairs (1) Abaxial A A A P (2) Adaxial A AA P 5. SHEATH (adaxial margin) a. Hairs A A A P b. Length (cm) 1.8b 1.8b1.5b 2.1a 6. COLLAR (1) Hairness P P P P B. Floral Traits 1. MALE A A AP INFLORESCENCE 2. FEMALE P P P P INFLORESCENCE a. Stigma color purplepurple purple purple b. Spikelet (1) Number of burrs 2.6c 4.5a 3.8b 4.5a(mean of 10 spikelets) (2) Burr length (mm) 3.2c 4.4b 4.0b 6.5a (3) Burrwidth (mm) 2.7b 4.2b 4.4b 6.2a (4) # Flowers per burr 2.4a 2.5a 2.5a2.5a (mean of 10 flowers) 7. Chromosome number 20 20 20 60 (2n) *Meansseparated by Duncan's new multiple range test, P = 1%

It is apparent from the above data that the new cultivar of the presentinvention displays shorter internodes and thinner stolons than thecomparative cultivars. Also, ‘UCD-95’ exhibits a lesser number of burrsper spikelet, smaller burrs, and a lesser number of flowers per burr.

TABLE 2 Turfgrass Overall Quality Rating of ‘UCD-95’ in Comparison toTwo Other Diploid Buffalograss Varieties and the Old HexaploidBuffalograss Cultivar ‘Texoka’ Over the Growing Season of 1995 UnderField Management Conditions. Turfgrass quality ratings 1 to 9 where 9 isideal turf MAY JUNE JULY AUG. SEPT. NOV. MEAN ‘UCD-  9a* 9a 9a 9a 9a 9a9.0a 95’ ‘Hilite 6b 7b 7b 7b 7b 7b 6.8b 25’ ‘Hilite 6b 7b 7b 7b 7b 7b6.8b 15’ ‘Texo- 3c 5c 5c 5c 4c 1c 1.0c ka’ *Means separated by Duncan'snew multiple range test, P = 1%.

The turfgrass quality is based on uniformity, density of stand, textureof turf canopy, smoothness of surface, and growth habit (Beard J. B.,Turfgrass Science, 1973). The field trials were conducted at Davis innorthern California and at Riverside in southern California, U.S.A.Superior turf quality was consistently displayed by the new ‘UCD-95’cultivar of the present invention under field growing conditions.

TABLE 3 Performance of ‘UCD-95’ in Comparison to Two Other DiploidCultivars and the Old Hexaploid Cultivar ‘Texoka’ for SpecificCharacteristics. Character (1 to 9 scale where 9 is best) ‘UCD-95’‘Hilite 25’ ‘Hilite 15’ ‘Texoka’ Rate of vegetative spread  9a* 7b 7b 4cTurf density 9a 9b 9b 7c Injury regrowth potential 9a 7b 7b 4c Shadetolerance 9a 7b 7b 3c Genetic color 9a 9b 9b 6c Fall turf green 9a 7b 7b4c color retation Heat tolerance 9a 9a 9a 9a Drought tolerance 9a 9a 9a9a Salinity tolerance 8a 8a 9a 8b *Means separated by Duncan's newmultiple range test, P = 1%.

It will be noted that ‘UCD-95’ was superior or equal to the othercultivars for all characteristics identified in Table 3 except salinitytolerance where it was exceeded only by the ‘Hilite 15’ cultivar. Thefall turf green retention characteristic and the rate of vegetativegrowth for the new cultivar were particularly superior when compared tothe other cultivars.

TABLE 4 Dry Weight Allocation in Above Ground Reproductive andVegetative Plant Parts As Percent of Total. Dry Weight (Percent)‘UCD-95’ ‘Hilite 25’ ‘Hilite 15’ ‘Texoka’ Reproductive Parts Greenhousegrown with-  22c* 53a 41b 55a out cutting back Field grown under 5 52b62a 60a 58a cm mowing height Vegetative Parts Greenhouse grown with- 78a47c 59b 45c out cutting back Field grown under 5 48a 38b 40b 42b cmmowing height *Means separated by Duncan's new multiple range test, P =1%.

The dry weight allocation measurement was conducted in August of 1997during the peak season for the development of sexual reproductive parts.It will be noted that a greater dry weight allocation in the vegetativegrowth and a lesser dry weight allocation in the reproductive parts isdisplayed by the new cultivar of the present invention when compared tothe previously released cultivars.

TABLE 5 Comparative Weed Competitiveness Study Ratings on Scale of 1 to9 Where 9 Equals “No Weeds” and 1 Equals “Complete Weed Cover”.Buffalograss Cultivars January March June July Mean ‘UCD-95’ 9 9 9 99.0a* ‘Bonnie Bare’ 4 5 6 5 5.0f ‘378’ 7 6 5 5 5.7f ‘92-118’ 9 8 9 98.7a ‘Midget’ 9 8 8 7 8.2b ‘609’ 9 8 8 8 8.2b ‘Cody’ 6 6 4 6 5.5f‘Texoka’ 6 7 8 6 6.7e ‘Bam-1000’ 7 8 7 7 7.2d ‘Bison’ 5 3 4 4 4.0g‘Stampede’ 9 9 9 8 8.7a ‘Tatanka’ 6 7 9 9 7.7c ‘86-120’ 5 2 6 4 4.2g‘86-61’ 4 2 5 4 3.7g *Means separated by Duncan's new multiple rangetest, P = 1%.

The weed study was conducted in year 2000 in the field at a southernlocation of Riverside, Calif., U.S.A., when plants were mowed to aheight of 7.5 cm. The weeds were predominantly dichondra, oxalis,dandelion, and annual bluegrass. The superior weed competitiveness ofthe new cultivar of the present invention was displayed. Weeds could notcompete well with the new cultivar at any time during the growingseason.

References Cited

Stebbins, G. L., (1975) “The Role of Polyploid Complexes in theEvolution of North American Grasslands”, Taxon, 24(1):91 to 106.

Reeder, Jr., (1971) “Notes on Mexican Grasses IX MiscellaneousChromosome Numbers-3”, Brittonia, 23:107 to 117.

Wu, L., and A., Harivandi, (1995) “Buffalograss Response to Cold, Shade,and Salinity” California Turfgrass Culture, 45:7 to 10.

Wu, L., and H. Lin, (1994) Salt tolerance and salt uptake in diploid andpolyploid buffalograss (Buchloe dactyloides). J. Plant Nutr.,17: 1905 to1928.

Lin, H., and L. Wu, (1996) “Effects of Salt Stress on Root PlasmaMembrane Characteristics of Salt-Tolerant and Salt-SensitiveBuffalograss Clones” Environmental and Experimental Botany, 36:239 to254.

Wu, L., Xun Guo, and Ali Harivandi (1997) “Allelopathic Effects ofPhenolic Acods in Buffalograss (Buchloe dactyloides) clippings on Growthof Annual Bluegrass (Poa annua) and Buffalograss Seedlings”Environmental and Experimental Botany, 39:159 to 167.

We claim:
 1. A new and distinct cultivar of Bachloe dactyloides planthaving the following combination of characteristics: (a) stolons of finetexture, (b) superior drought tolerance, (c) a competitive growth habit,(d) short winter dormancy, (e) superior turf green color retention, and(f) high turf density with a rapid stolon spreading rate and short plantheight that provides a low maintenance turf; substantially asillustrated and described.